President Trump will interview four candidates on Sunday to replace his dismissed national security adviser, three of them military veterans. Trump, who is spending the weekend in Florida, will also interview John R. Bolton, who served as President George W. Bush’s ambassador to the United Nations and has previously been considered for deputy secretary of state. Sean Spicer, the White House press secretary, told reporters that “potentially others” might also be considered but that David H. Petraeus, the retired general and former C.I.A. director, was not a candidate.